METHOD FOR CONTROLLING GAIN OF LOW NOISE AMPLIFIER IN MOBILE COMMUNICATION TERMINAL

摘要

PURPOSE: A method for controlling the gain of an LNA(Low Noise Amplifier) in a mobile communication terminal is provided to minimize the current consumption and to improve the quality of call by controlling the gain of an LNA to three step of high, middle and low according to gain control signals outputted through the PDM(Pulse Duration Modulation) port of an MSM(Mobile Station Modem). CONSTITUTION: An LNA(11) performs uniformly leveled low noise amplification for RF signals according to gain control signals outputted through the PDM port of an MSM(15). A frequency converter(12) carries out frequency down conversion for the amplified RF signals into IF(Intermediate Frequency) signals. An Rx AGC(Automatic Gain Control) part(13) controls so that the gain of the converted IF signals can be maintained uniformly. A BBA(Base-Band Analog processor)(14) converts the IF signals passed through the Rx AGC part(13) into base-band digital signals. The MSM(15) outputs the gain control signals to the LNA(11) and the Rx AGC part(13) through the PDM port.